GB944909A - Improvements relating to heavy metal-containing formazane dyestuffs and their use - Google Patents

Abstract

The invention comprises dyes of formula <FORM:0944909/C3/1> wherein A and B are aromatic radicals of the benzene or naphthalene series which contain the -COO- group in A in ortho position to the azo group and the -O- group in B in ortho position to the hydrazo group, Me is copper or nickel, R is an aromatic radical of the benzene or naphthalene series, Y is an aliphatic, cycloaliphatic or aromatic hydrocarbon radical containing at least 4 carbon atoms which is bound to a nuclear carbon atom of the formazane dye by an -SO2-, -SO2NR1- (R1 being hydrogen or an aliphatic, cycloaliphatic or aromatic hydrocarbon radical), -SO2O-, -SO2NH- -CH2- or -CO- bridge and n is 1 or 2. The dyes are prepared by treating with a copper or nickel-yielding agent a formazane dye of formula <FORM:0944909/C3/2> or by first treating a metallizable monoazo dye of formula <FORM:0944909/C3/3> wherein D is the group A-COOH or B-OH with a copper- or nickel-yielding agent and then coupling with a diazonium compound from an amine of formula <FORM:0944909/C3/4> the components being such that the metallized formazane dye contains 1 or 2 Y groups. The intermediate formazane dyes are prepared by known methods. The dyes free from water-solubilizing groups are used as pigment dyes to colour lacquers, varnishes or acetyl cellulose or polyamides in the mass. The dyes containing water-solubilizing groups are used to dye and print leather, paper, silk, polyamide or polyurethane fibres and particularly wool, in blue shades. In examples: (1) the diazo compound of 2-amino-phenol-4-sulphonic acid N-(21-chlorophenylamide) is coupled with the hydrazone from phenylhydrazine-2-carboxylic acid-4-sulphonic acid and benzaldehyde and the formazane metallized with copper tetramine sulphate; (2) 2-aminophenol-4-sulphonic acid N - ethyl - N - phenylamide - 41 - sulphonic acid is diazotized and coupled in aqueous dioxan with phenylformyl acetic acid ethyl ester, the reaction mixture is made alkaline with sodium hydroxide and refluxed; the saponification product is treated with acetic acid and copper sulphate and finally reacted with diazotized 3,5-dichloro-2-aminobenzoic acid. Many further examples and alternative reactants are specified.